Coffee maker



Aug. 15, 1939. R. 's. McNElL corran: uAxEg Filedsapt. 10, 19:57

may

Inventor:

Patented Aug'. l5, 1939 PATENT oFI-lcE-gj coFFE'MAxEa Roderick S. McNeil, Bridgeport, Conn., assignor to General Electric Company, a corporation of New York Application September 10, 1937, Serial No. 163,279

Claims.

This invention relates to coilee makers, and lt has for its object the provision of an limproved device of this character.

This invention contemplates animproved coee 5 maker which heats the water to the proper temperature, and brings it into contact with the coffee grounds under such conditions that a coffee brew is produced having an excellent avor, and one that is free from coffee grounds.` In accordance vwith this invention in one form thereof, the water is heated to the proper temperature and is forced under pressure into a container in whlch'the coiee grounds are placed. The container is provided with a discharge port before which is placed a dam which consists of a screen having a very ne mesh. The mesh is so fine that coffee grounds will not flow through it but will build up a dam of grounds so that the coffee brew must be forced through the dam and and layer of coffee grounds covering it set up a back pressure to the admission of water to the ground coffee container. The coffee grounds are thus steeped by heated water under a slight pressure.

Preferably, the ground coffee container will discharge into a receptace that is separate from the water heating vessel, the ground coffee container receiving the heated water from one vessel and discharging the prepared coffee brew into another. I For a more complete understanding of this invention, reference should be had to the accompanying drawing in which Fig. l is a vertical sectional view of a coiee maker embodying this invention; Fig. 2 is a plan view of the coiee maker of Fig. 1, parts being broken away so as to illustrate certain details of construction; Fig. 3 is a vertical sectional view illustrating a coffee maker of modied form arranged in accordance with this irivention; and Fig. 4 is a vertical sectional view illustrating still another modied form of this invention. y

Referring more particularly to Figs. 1 and 2, this invention has been shown as applied to a coiee maker having a relatively deep -vessel I0, preferably Ahaving a cylindrical side wall I0a and a bottom 4wall IIJb. Inserted in this vessel is a lcylindrical partition II dividing it into inner and outer compartments I2 and I3. As shown, the lower section I Ia ofthe dividing member has the shape of a truncated cone the base of which rests on the bottom wall IDb of the vessel I0, and the upper end of which merges into an upright smallscreen under pressure. In other words, the screen` er cylindrical part IIb. The upper end ,of the (ci. sus) portion IIb is open, as shown, and ls brought up tosubstantlally the level of the upper edge of the vessel I0. The chamber I3 constitutes a water heating compartment, while the chamber I2 'serves to receive the nlshed coffee brew. 5

Positioned within the compartment I2 is a ground coee compartment I4 for receivingthe coffee grounds. The compartment I4 is of annular form and is defined by substantially cylindrical'spaced apart inner and outer walls I5 and 10 I6 joined at the bottom by a bottom wall I1. The inner wall I5 is arranged to be tted relatively closely to the upright section IIb ofv the dividing member, as shown. VThe container is supported on this section lin any suitable man- 15 ner, as by means of a seat I8 secured to the member and upon which the coffee container rests. As shown, when the coffeecontainer is on its seat I8, the upper edge of the inner wall I5 comes substantially to the upper edge of the portion ,20 IIb, while theouter wall I6 extends somewhat' 1 above the plane of this upper edge and that of the vessel I0.

It will' be observed that the inner and outer walls I5 and I6 of the coffee container as well as the bottom wall I1 are imperforate except fora relatively smallv area of the outer wall I6 which is open to define a discharge port I9. As shown, this port is arranged at one side of and adjacent the bottom wall I1, and it extends through a por- `30 tion of the 'circumference of the outer wall L6 between the points 20 and 2l. The port I9 is closed by a vertical screen dam 22 which preferably will be made of metal and which will have a very fine mesh, suchas 200 to the square, inch.. 35

is placed onit. It will be observed that when the 40 cover is in place, the container is a closed compartment, except for the port I9.

Heated water under pressure is introduced to the chamber I4 fromethe water heating compartment I3 by means of a delivery tube 25 which is 45 inserted through the upper open mouth ofv the inner compartment, as shown, and which is supported by means. of a member 26. The member 26 has a supporting plate 21 through which the upper end of the tube 25 is directed, as shown vin Fig. 1, and to lwhichvthe tube is secured in any suitable manner, as by brazing. orwelding. Extending upwardly from the periphery of the plate 2l is a circular wall 28which is provided with a series of spaced openings 29. The plate 2l and 55 open at the top, but which is closed by the sealing member 24 when the cover 23 is placed on the co'ee container. A sealing member 30a is carried under the plate 21 so as to bear on the upper edge of the section I Ib and also that of the inner wall I5.

The vessel IU is provided with a cover member 3I which may be secured to the vessel in any suitable'manher yasby means lof dbayonet joints 32. The co'ver 3l carries'a screw 33 threaded through it substantially centrally thereof, as shown in Fig,

1', and whose lower end is adapted to bear upon the cover 23 for the coiee compartment to force the cover intoliquid-tight engagement with the side walls of the compartment. The parts are so arranged that when the screw 33 is turned inwardly to effect this seal between the cover 23 and its compartment, it at the same time effects a liquid-tight seal between the sealing member 30a and the upper endges of the inner wall I5 of the coffee compartment and the member I Ib.

In the operation of the device, it`will be understood that to make coffee, the covers 3| and 23 and the member 21 carrying the delivery tube 25 will be removed from the vessel I0. The prop er amount of water will then be placed into the compartment I3, and the proper amount of coffee grounds will be placed in the ground coffee conconnection 32. The screw 33 will then be turned inwardly so as to seal the vessel I3 and the coffee container.

When heat is applied to the bottom wall I0b of the coffee maker, the water-within the inner cornpartment will be heated and as its temperature israised vapor pressure will be generated within the compartment. 'Eventually when this vapor pressure attains a predetermined value, which will occursubstantially at the boiling point of the water, the heated water will be forced up through ,the tube 25 and into the compartment 30 from which it will discharge radially through the openings 29. The water that is thus discharged is spread over the entire upper area ofthe coffee grounds placed within the compartment I4. The water that is forced into the compartment steeps the grounds placed within it to make the` coffee brew. 'I'he discharge of the prepared brew from the compartment is resisted by the screen 22 whose mesh, as pointed out previously, is so ihe that it will cause a back pressure to be generated in the compartment. I'he screen is so ne that water supplied to the compartment I4 will not flow readily through it lby gravity, but must be forced through it under a pressure the magnitude of which depends upon the iineness of the screen,

It is important that the screen have such a fineness that it will retain even the ner of the coffee grounds. These will collect in a layer before the screen and will form a dam or filter of the grounds themselves. The pressure necessary to force the coffee brew through this layer of coffee grounds and the fine screen'is supplied by the generation of pressure in the chamber I3.

It will be observed in View o-f this arrangement that `the heated water is forced through the groundcoffee in the compartment I4 under pressure and that the coffee brew which is made by .spaced somewhat from the bottom wall IIJb of the ycoffee maker so that some water will be left in the water heating compartment I3 after the coffee is made. This water may be heated and used to keep the coffee brew warm. Thesteam generated by heating this water is forced through the coffee container which dries thecoiee grounds and prevents dripping from the container after the coffee is made.

It will be understood that any suitable heating means may be used. Thus, for example, the coiee f maker may be provided with an electrically heated hot plate. I

In Fig 3, there is illustrated a modified form of this invention. In this case, the coffee maker is provided with compartments 36 and 31 rranged one above the other, as shown. The lower compartment 36 which is the larger of the two is the water heating compartment, while the upper compartment 31 receives' the coffee grounds. The lower' compartment 36 is provided with a lier lspout 38 which is closed by a stopper 39. The vessel is otherwise closed except for its connection with the ground coffee receptacle by means of a water delivery tube 40, 'Ihe ground coffee con tainer 31 is provided with an opening 4I at the top through which the coffee grounds are inserted, and whichnormally is tightly closed by a cover 42.` The container is provided in its side wall with a discharge port 43 that discharges into a spout 44. Positioned over the port 43 is a screen darn 45 which has essentially the same characteristics as the screen dam 22 of the iirst form. Preferably andas shown, the tube 40 will enter the compartment 31 at one side thereof and the discharge port 43 will be positioned at the opposite side.

The water in the vessel 36 is heated by the electrically heated hot .plate 46. This hot plate is controlled by a thermostatic switch 41 comprising a bi-metallic thormostat bar 48 that operates a switch 49. The switch is connected in the energizing circuit of the plate 46 and when closed completes this circuit and when opened by the thermostat opens the circuit.

In operation, the water that is placed within the compartment 36 is heated by the plate 46 and forced up through the tube 40 into the ground coffee compartment 31 where the ground coffee is steeped, 'I'he coffee brew that is formed is forced through the screen dam 45 and out through the discharge spout 44. A suitable receptacle (not shown) will be placed under the spout to collect the coffee brew. Here again, the screen dam 45 sets up a back pressure so that the grounds are steeped under pressure.

When substantially all of the water above the level of the lower end of the tube 4I) has been forced out of the vessel 36, the temperature of the lower Walls of this vessel will increase rapidly to the temperature at which the thermostatic extension 56 which Will extend into a vessel 51 placed under the spout forthe reception of the coffee brew. The advantage of this construction over 'that shown in Fig. 3 'is that after the coiee has been made and the residual water in the vessel 5U below the lower end of the tube 52 is heated, the steam that is generated will be` forced down through the member 56 and into the brew in the vessel 51. The steam in bubbling up through the brew keeps it warm.

In each case, the water is heated almost to the boiling temperature and is then forced into and through the coffee grounds. 'I'he pressure Ais sufficiently h'igh to quickly force the Water through the coffee maker so that it 'contacts the coffee grounds for but a relatively short interval of time.

The time of contact is such that only the desirable essences are lobtained; the bitter oilsv are not absorbed. Andl in each case the grounds are substantially dried by the passage of steam through them after the major portion of the water has been transferred from the water heating compartment.

While -I have shown particular embodiments of my invention, it will be understood, of course, that I do not Wish to be limited thereto since l many modiiications may be made, and I, therefore contemplate by the appended claims to cover any such modiiications as fall Within the true spirit and s'cope of my invention.

What I claim as new anddesire to secure by Letters Patent of the United States, is: y

1. A coiiee maker` comprising a compartment for heating water having an opening in its upper end through which water is introduced, a water delivery tube of relatively small diameter inserted through said opening, a supportl for said delivery tube arranged to be fitted to said opening to close it to prevent loss of pressure fromthe compartment, a water delivery chamber above said opening and connected with the discharge of said tube, the delivery chamber providing for radial disposition of the water fed to it from the tube, a

closed container for' coffee'grounds around the compartment and arranged sothat the water vessel for receiving coffee brew, a ground coii'ee compartment arranged within the space between said compartments and having a port discharging into the outer compartment, a relatively small water delivery tube inserted through the top of said inner compartment, a cover for said top 'Ihe valve remains `closed. until the water supporting the tube and having a water` delivery chamber connected with the tube and providing vfor radial disposition of the water fed into it from the tube to the coffee container, a common lid for said coffee containervand water delivery chamber, and means forcing said lid-into liquidtight t with said members.

3. A coffee maker comprising a pair of opentop compartments arranged in substantially concentric relation, the inner compartment constituting a water heating vessel and the outer vessel for receiving coiee brew, a ground coiee container arranged within the space between said compartments and having a port discharging into thel outer compartment, a relatively small waterdelivery tube inserted'through the top of said inner4 compartment, a coverv for said top supporting the tube and having a water delivery chamber connected with the tube providing for radial disposition to the coiee container of the water fed into the delivery chamber from the tube, a common lid for said coffee container and water delivery chamber arranged to have a liquid-tight t with said members, a cover for said outer compartment, means securing said cover to said outer compartment, and a screw inA said cover arranged to be turned inwardly to force-said lid into liquid-tight iit with said ,coifee container and water discharge member and to force the latter member into liquid-tight t with said lnner compartment. n

4. A coffee maker comprising inner'and outer substantially concentric open-top compartments,

the inner constituting a wat'er heating vessel, a discharge spout on the outer compartment, a

'ground coffee container around the inner compartment, discharging into the outer, a lid for said ground coffee container having a sealing member engaging the mouth of said container, a second lid for said outer compartment over the first lid, means securing said second lid to the outer compartment, means carried by the second lid for forcing said rst lid into liquid-tight fit with said coffee container, a member interposed between the upper end of said inner compartment and said rst lid having a sealing member arranged to be tted to and close the mouth of said inner compartment and having a chamber closed at the top by the sealing member on the iirst lid, a water delivery tube carried by said member inserted insaid chamber, and the chamber having a series of lateral ports discharging into said coffee container. A

5. A coffee maker comprising a pair of opentop compartments arranged in substantially concentric relation, the inner compartment constituting a water heating vessel and the outer a vessel for receiving coffee brew, a ground coiIee compartment arranged within the space between said' compartments and having a port discharging into the outer compartment, a relatively small water delivery tube inserted through the top oi' said inner compartment, a cover for said top supporting the tube and having'a water delivery chamber connected with the tube and providing for the discharge of the water fed into it from the tube to the coiee container, a common lid for said coffee container and water delivery chamber, and means forcing said lid into 'liquidacht at with said members. v

. RODERICK S. MCNEIL.

.to said inner compartment and discharging into 

